Name: Three Gorges Dam Location: Located on the Yangtze River in Sandouping, southern China. Coordinates: 30 49' North 111 00' South. Dam type: Concrete gravity dam. Length of the dam: 2.3 km. Height of the dam: 185 m. The materials used are: Cement (10.82 million tons), Concrete (26.4 million m3), Rolled steel (1.92 million tons), Wood (1.6 million m3). Construction period: 1993-2009 Construction cost: 25 billion US dollars. Expected life: 100 years. Climate data: Average maximum temperature: 32 degrees. Average minimum temperature: 2 degrees. Some statistics about the dam: Reservoir capacity: 1.39 trillion cubic feet. Electricity Production: 18,000 megawatts. Gravity Dams: A gravity dam is made of concrete or masonry, or sometimes both. It is called a gravity dam because gravity holds it to the ground by stopping the water in the reservoir, pushing it past it. Section cross section of the gravity dam similar to a triangle. Gravity dams are built primarily across wide or narrow valleys, but must be built on strong rock. Dam construction sequence: Dam construction (material requirements and its properties) Concrete construction operations are of vital importance to the designer of the structure. The safety of any structure is related to certain design criteria which include the safety factor. Design requirements: Basically a concrete structure must be able to provide the intended use for a long period of time. To serve its purpose, concrete must have high strength to support design loads safely and efficiently. The concrete running through the structure must be of uniform quality because the structure is... middle of paper... but this higher strength concrete is not desirable from a design economic perspective. In cold climates where freeze-thaw cycles occur frequently, it is advantageous to use a special mix for the dam face concrete to ensure adequate durability. A higher cement content and a lower water/Portland cement ratio, or when the mix contains pozzolan in the outer portions of the dam a lower water/Portland cement plus pozzolan ratio is often used. There may be some variation in the mix due to changing characteristics of the cement and aggregates used in the design of the structure. The amount of cement to be used per cubic meter of concrete is determined by mixing investigations which primarily aim to achieve the desired strength and durability of the concrete. The type of concrete should be determined by other design considerations.